Discovery Insure

I've recently cancelled my car cover purely on the basis of high premium. January debit order was R1952.56 for a 2012 car with R3600 excess. I've managed to get a more affordable comprehensive cover through SouthSure Brokers for R1125.75 with no basic excess. Discovery Insure then offered me the R1808.37 which I turned down. I was then told after cancelling that I would forfeit the R900+ amount which I have accumulated in the excess fund amount. This is the 'monthly fuel cash back payment' which would have been paid monthly into my bank account but I was sold the option to rather have this deposited into the excess fund account. I find this unfair to me as a consumer on the basis that had I been told that if I cancel I would forfeit what I have accumulated, I would have NEVER chosen this option. I really feel hard done. The agent I spoke to was dismissive to my complaint and simply told me 'that's how it works'. This has left a bitter taste in my mouth and I feel hard done!